Released by the China Law Society, the report on China's legal system construction in 2012 said a total of 13,248 companies were linked to the monitoring center of the Ministry of Environmental Protection (MEP) by the end of the year.

The report also applauded the authorities' intensified efforts in publishing environmental monitoring results.

A total of 496 monitoring sites in 74 cities are monitoring and releasing data on six gauges of pollution, including SO2, PM10 and PM2.5, in real time, according to the report.

They are also publishing information on air quality indices (AQI), the report added.